Development of microfilariae of two bovine Onchocerca species in blackflies in Japan.

Abstract

Injections of blackflies with two types of bovine Onchocerca microfilariae able from O. gutturosa and O. gibsoni so far reported from Japanese cattle.

Infective larvae of fiveOnchocercaspecies from experimentally infectedSimuliumspecies in an area of zoonotic onchocerciasis in Japan

“…The present study shows that O. lienalis develops in S. arakawae. The two infective larvae obtained are similar to that found by Takaoka (1990) following injection of microfilariae from cattle in S. arakawae, and to the type III from wild-caught S. arakawae (Takaoka & Bain, 1990). Thus S. arakawae is also a vector of O. lienalis.…”

“…Unlike Onchocerca species from African suids, the two species recovered from wild boar lacked a characteristic caudal point (Wahl & Bain, 1995). Other morphometric characters were more constant ( An identification key is proposed on the basis of the present study (Table VI), and published data (Table VII) concerning O. lienalis and O. gutturosa from experimental cycles in simuliids and Culicoides in Europe (Supperer, 1952;Bain, 1979), and the infective larvae obtained from injected microfilariae from cattle (Takaoka, 1990) and those found in wild black flies collected at cattle shed in Oita (Takaoka & Bain, 1990;Takoaka, 1994 Takaoka & Bain, 1990;Takaoka, 1994. e 650 µm in Steward, 1937.…”

“…Thus S. arakawae is also a vector of O. lienalis. No infective larvae resembling type I (Takaoka, 1990(Takaoka, , 1994Takaoka & Bain, 1990) were obtained with the Onchocerca microfilariae injected in this study. …”

“…of wild boar, and O. lienalis, and determined the ability of simuliids to support development of infective larvae. The morphological characteristics of infective larvae recovered from experimental infections were compared with those of infective larvae previously described in Oita (Takaoka, 1990(Takaoka, , 1994Takaoka & Bain, 1990), and the criteria for identification of the infective larvae found in local black flies were reevaluated.…”

“…To investigate the transmission and the background of this zoonotic onchocerciasis, we have examined filariae from wild ungulates in Japan, the wild boar Sus scrofa Linnaeus, 1758, the sika deer Cervus nippon Temminck, 1838, the serow Naemorhedus crispus (Temminck, 1845), as well as cattle (Bos taurus), and the putative vectors, the black flies (Diptera: Simuliidae). These studies showed a great diversity among the genus Onchocerca as well as other Onchocercinae (Takaoka et al, 1989;Takaoka, 1990Takaoka, , 1994Takaoka & Bain, 1990;Yagi et al, 1994;Uni et al, 2001Uni et al, , 2002Uni et al, , 2004Uni et al, , 2006Uni et al, , 2007. The picture of the filarial fauna is however still incomplete, and a few kinds of microfilariae, without corresponding adult worms, remain unidentified.…”